Impacts of Pit Latrine Additives on Volatile Solids and E. coli in Faecal Sludge

Toilet chemical additives and their effect on faecal sludge characteristics

“…On the other hand, mass loss achieved by the 5 g calcium carbide treatment (C1) could be due to a probable optimum biochemical degradation that was aided by a comparatively moderate quantity of the carbide additive used. In this case, the complex relationship among temperature, moisture content, pH and biodegradation processes could have partly enhanced microbial decompositions of faecal sludge as well [ 1 ]. The mass loss in the control may also be largely due to dehydration (loss in moisture content), and also biochemical degradation of faecal sludge content [ 17 ].…”

“…In recent years, the use of toilet additives to treat faecal sludge in domestic sanitation facilities has received increasing attention [ 1 , 2 , 3 ] partly due to large sludge generation and stringent environmental management regulations [ 4 ]. Domestic faecal sludge is raw or partially digested slurry or semisolid usually generated from on–site toilet systems [ 5 ].…”

“…Major faecal sludge problems include finding safe handling and appropriate disposal options especially in developing countries [ 2 ]. Untreated faecal sludge is laden with pathogens which could cause illnesses such as diarrhoea, cholera and dysentery [ 1 ]. Safe disposal of faecal sludge into the environment will require treatments to sanitise (kill pathogens) and also to stabilise faecal matter (reduce vector attraction) [ 1 , 6 ].…”

“…[ 7 ], toilet additives whether in their inorganic or organic forms have found application in enhancing faecal sludge treatment. These additives increase processes like faecal sludge decomposition and dewatering which result in reduction of sludge volume and pathogenic loads [ 1 , 8 , 9 ]. Chemical and biological processes involving the use of additives like ash, urea, lime, and lactic acid have been investigated for their efficacy in treating faecal sludge [ 6 , 8 , 9 , 10 ].…”

“…Despite these promising claims, the effectiveness of toilet additives in reducing sludge volume is still under rigorous interrogation and debates [ 3 ]. Some studies on additives capabilities give mixed results - while some link significant sludge volume reduction and sanitization to additives [ 6 , 15 , 16 ], others claim otherwise or at best state “no evidence linking additives to faecal sludge decomposition and sanitization [ 1 , 2 , 7 , 17 , 18 ]. Kemboi et al., [ 1 ] however, attribute the differences in results to the difference in the active compounds/enzymes found in additives and the methods of application, yet that is a valid contribution to the ongoing intellectual debate.…”